Development and Evaluation of a GPS-Based Weeding System for Reducing the Risk of Musculoskeletal Disorders among Agricultural Workers Consistent with other industries, musculoskeletal disorders (MSDs) are the most common of all occupational injuries and illnesses in agriculture. MSDs in agriculture are commonly reported at rates near or above those of traumatic injury, respiratory illness, pesticide-related injury or illness, dermatological injury or illness, or other types of injuries and illnesses. It is evident that low back disorders (LBDs) are by far the most prevalent and costly injuries in most industries, including agriculture. Weed control is a very important issue for farmers, particularly for those producing vegetable crops. Weeds are currently controlled by chemical herbicides and manual weeding, which is a strenuous task that exposes agricultural workers to various MSD and LBD risk factors. At this stage, there are limited alternatives to manual hoeing and herbicide application to effectively control weeds in vegetable crops. There is clear need to develop new and innovative methods of weed control in order to reduce the risk of musculoskeletal disorders associated with weed control, to reduce the introduction of herbicides into the environment, and to increase the competitiveness of farmers. Hence, the specific aims for this project are: 1) Develop a global positioning system (GPS)-based approach that can accurately map the location of each crop plant during transplanting, 2) Develop a weed knife system to remove weeds growing between the crop plants: a) Develop a GPS-controlled automatic weed knife for controlling weeds between plants;b) Develop the cutting system in such a way as to allow manual activation for use by small farmers and/or farmers who do not own a GPS system;3) Develop a manual tool to replace traditional hand hoeing for precision weed control in areas close to the crop plant;and 4) Conduct biomechanical and subjective evaluations of the potential reduction in MSDs due to the newly developed approach as compared to the existing manual system. Manual weeding is not unique to California, for it is performed in almost every vegetable crop in the US, and hence;the implications of this study should apply to other regions that have crops requiring manual weeding. The project findings can be translated into actual modifications to existing practices, especially for farmers who are already using the GPS technology. From a worker's health perspective, the proper implementation of the proposed weed control approach could translate into substantial savings in medical and other costs, and in reduced lost workdays and worker disability. Further environmental and health benefits could be realized by the elimination for the need of herbicides in areas where weed is controlled by the proposed system. Public Health Relevance: Musculoskeletal disorders in agricultural settings are the leading health problem for farmers and farmworkers. Agricultural workers who perform manual weeding are exposed to several musculoskeletal disorders (MSD) risk factors. If the study shows that the proposed weeding approach considerably reduces low back disorders risk factors, and the reporting of MSD symptoms among the targeted population, the implications for all workers who perform weeding and thinning tasks (and their employers) in agriculture could be substantial. The proper implementation of the proposed weed control approach could translate into substantial savings in medical and other costs and in reduced lost workdays and worker disability. Further environmental and health benefits could be realized by the elimination for the need of herbicides in areas where weed is controlled by the proposed system. In addition, increased availability of precision mechanical weeding methods should result in reduced use of pre-plant soil fumigation. Soil fumigants are highly toxic and, as volatile organic chemicals, contribute substantially to smog formation.